Wind power is another alternative energy source with possible application to the proposed Arecibo RO WTP. Windmills have been used for hundreds of years with the purpose of utilizing another natural resource to provide power. The modern revival of the windmill is a wind turbine, which consists of a few thin blades that maximize the percentage of kinetic energy extracted from wind mass.
Wind turbines are capable of using the converted kinetic energy to generate electricity that can be used for residential needs as well as for businesses and other establishments (American Wind Energy Association, 2009). The proposed turbines consist of a vertical tower with an alternator, which usually consisting of a jet turbine which converts of the wind’s kinetic energy. The alternator of our turbines has vertical axis on the tower (Global Clean Energy , 2010).
The energy carried in wind increases with wind velocity. The direct conversion of wind energy into kinetic energy is completed by the turbine blades. The area of wind passing through the blades at any given time correlates to the amount of mechanical energy that can be obtained. Therefore, larger turbines with a greater surface area will harvest the largest amount of power from the wind and are the most efficient in converting the wind’s energy into electricity (World Wind Energy Association, 2006). Because this method directly harvests power from the wind, it has many environmental and social advantages.
Wind turbines can be utilized as either individual harvesters of energy or as collective harvesters in systems. Individual placement of wind turbines is not very conducive to generating large amounts of energy and therefore would be better suited for minor energy demands. Aside from the quantity of wind turbines, the location of their placement is also critical in obtaining energy (Muljadi, 2006). Wind turbines can be constructed on land or offshore.
Changes in wind direction and velocity can affect the consistency and efficiency of its energy conversion (Rowlands & Jernigan, 2008). This problem has two possible solutions that SolaryA explored to determine the feasibility of using wind turbines.
The first option is to create a form of storage for the energy converted by the wind. This would address the problems that variable wind patterns create when the wind has stopped and no electricity can be generated. If the energy were stored, it would be able to provide for disruptions in power and act as a backup generator in those types of situations. The wind is also variable from day to night, with higher and more consistent velocities during the day as opposed to at night, so the storage system would also be effective for overnight and slowed velocities (Rowlands & Jernigan, 2008).
The second method is to connect the turbine system directly into the electrical grid of the power plant to prevent the need for any type of storage system. This proposed method is referred to as the “Danish Concept” and has been used across Europe (World Wind Energy Association, 2006). The electricity flows directly to the grid to provide for any possible disruptions to consistently meet the base load (Danish Wind Industry Association, 2003). However, one case study reported a downside to this method.
According to a 2008 case study of wind energy in Ontario, Canada, if the turbines were directly connected to the power grid and wind production fluctuated, it could have damaging effects on the power plant’s electrical grid. The load following requirement, which is the amount that generators/alternators change their power output in response to power demands, could possibly be altered as a result of these fluctuations. The same problem could also occur with the operating reserves requirement, which is the back-up capacity stored for when power disruptions occur. Both of these requirements could be altered and therefore affect the entire electrical grid and system (Rowlands & Jernigan, 2008). Both methods were explored in determining the most effective and feasible operating system for wind turbines.